docs: def write_into(self, output_file, eol=None):
          """
          write_into(output_file [, eol])
  
          Serialize current state into `output_file`.
  
          `output_file` -> Any instance that respond to `write()`, typically a
          file object
          """
          output_eol = eol or self.eol
  
          for item in self:
              string_repr = str(item)
              if output_eol != '\n':
                  string_repr = string_repr.replace('\n', output_eol)
              output_file.write(string_repr)
              # Only add trailing eol if it's not already present.
              # It was kept in the SubRipItem's text before but it really
              # belongs here. Existing applications might give us subtitles
              # which already contain a trailing eol though.
              if not string_repr.endswith(2 * output_eol):
                  output_file.write(output_eol)